This thesis explores the potential role of social enterprises as agents of technological change in developing societies. By ‘agents’ it is meant active participants in processes of conceiving and implementing new technological solutions for communities. The thesis argues that technology-oriented social enterprises can be effective agents of technology localization which includes diffusing, supporting and adapting technologies for local conditions. Technology localization is a main variable in the pursuit of technological autonomy in developing societies. Technological autonomy refers to the endogenous capacity of developing countries for generating, transferring and managing technologies on their own terms in support of economic and human development. The thesis examines 6 case studies of technology-oriented social enterprises in rural regions of Tanzania. The cases were headquartered in Tanzania but operated in other East African countries as well (Kenya, Uganda and Rwanda). To assess the effectiveness of the cases as agents of technology localization, they were assessed for their engagement in the activities of diffusion, support and adaptation, who they engaged with in these activities and whether their clients showed relative satisfaction with the technological change that the social enterprises promoted. Field data were collected from December 2014 to September 2015, through interviews with the staff, clients and partners of the social enterprises, as well as through field observations and scanning of accessible reports and documents of social enterprises and their partner organizations. The field work also identified three distinct models of diffusion represented by the cases: microfranchising, sector-enterprise cultivation, and business-technology incubation. All three models appeared effective as approaches to the diffusion of new technologies.